This type of chronograph watch conventionally includes a going train forming an energy transmission chain from an energy accumulator member, the barrel, to an energy distributor member, the escapement. This going train is generally formed of a centre wheel set, a third wheel set, and a chronograph seconds wheel set mounted in series between the barrel and the escapement. It further includes a permanent seconds wheel, secured to a permanent seconds display member, mounted in shunt from the third wheel set. Thus mounted, the permanent seconds wheel set is located at the end of gear train formed of the centre wheel set, the third wheel set and the permanent seconds wheel set.
Because of its location at the end of a gear train, the permanent seconds wheel set may rotate in an irregular jerky manner, which gives the permanent seconds display member a fluttering, imprecise appearance. This problem, well known to those skilled in the art, arises from the existence of a backlash, i.e. an angular play between the various wheel sets, provided for reasons of manufacturing tolerances, on the one hand, and in order to avoid a situation in which the gears are blocked, on the other hand. At the heart of a gear, the backlash is compensated for from one wheel set to another by the braking action exerted by the next wheel set, but at the end of the gear, as is the case of the permanent seconds wheel set, this braking action is non-existent and the backlash reverberates fully.
One solution for overcoming this problem consists in providing the permanent seconds wheel set with a friction device exerting axial friction able to suppress the random angular movements linked to backlash. EP Patent No 0 482 443 and CH Patent No 506 824 disclose devices of this type. It will be noted, however, that this type of solution is unfavourable from the point of view of energy consumption, because of waste generated by the friction.
The present invention proposes an alternative solution to the problem of fluttering of the permanent seconds display member that does not rely on a friction device and does not involve wasting energy. More specifically, the invention concerns a chronograph watch fitted with a going train, including:                a permanent seconds wheel set secured to a permanent seconds display member,        a chronograph seconds display wheel set cooperating with a coupling device in order to be connected to a chronograph seconds display member, and        a third wheel set including a first third wheel secured in rotation, meshed either with the permanent seconds wheel set or with said chronograph seconds wheel set.        